Reduction and Reductive Alkylation of α-tert-Butylthio Carbonyl Compounds. An Efficient Method for Stepwise α-Alkylation of Esters, Nitriles and Ketones Via the α-Tert-Butylthio Derivatives

Abstract

An efficient and generally applicable method for stepwise α-alkylatton of esters, nitriles, and ketones via the α-tert-butylthio derivatives is described. The method involves reductive-protonation and reductive-alkylation of α-alkylthio α,α-bis-alkylated carbonyl compounds which are prepared by stepwise alkylation of the corresponding simple α-alkylthio carbonyl precursors. The reduction is conveniently performed by use of stoichiometric amounts of a dissolving metal, particularly lithium, affording correspondingly the α-mono-and the α,α-bis-alkylated carbonyl compounds in good yields.